An advertisement in a 1915 MOTOR Magazine proclaimed:
"No slow thumb screw adjustment, but a lightning grip on any square nut from 1/4 in. to 3/4 in., and any hexagon nut from 7/16; in. to 3/4 in."

My wife's stepfather was a Railroad Enthusiast. He loved anything that had to do with trains.  Before the
1920's a local railroad shop in his town moved to another location. They furnished the new shop with all new tools and they disposed of all the old tools. In later years he acquired several of the tools from his father. He packed the tools in a wooden box and stored then. Shortly before he died in 2005, the box of "stuff" was given 
to me. Some of the old tools are pictured below.

The Cochran Speednut Wrench was made by the Cochran Pipe Wrench Mfg. Co. of Chicago and was patented by Walter W. Taylor, May 12,1916.

Below: A W&B  Railroad Special Warranted Monkey Wrench. All steel, 7 inches overall made by Whitman & Barnes.
Has S & G stamped on one side of the head. On both sides of the handle, W&B is stamped inside the Diamond logo.

An early adjustable wrench was the Cochran "Speednut" wrench.
                 It measures 9 inches overall.

The wrench above pre-dates the 1916 version when the pat. was released. On one side it reads Pat. Pending on the handle and Cochran Speed Wrench on the head. On the other side the lettering positions are reversed.

These old wrenches are in good condition. They work as well as they did back then in the Locomotive Shop.